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Eutheria (from Greek εὐ-, eú-'good, right' and θηρίον, thēríon 'beast'; lit. ' true beasts '), also called Pan-Placentalia, is the clade consisting of placentals and all therian mammals that are more closely related to placentals than to marsupials.
Figure 1:In mammals, the quadrate and articular bones are small and part of the middle ear; the lower jaw consists only of dentary bone.. While living mammal species can be identified by the presence of milk-producing mammary glands in the females, other features are required when classifying fossils, because mammary glands and other soft-tissue features are not visible in fossils.
A mammary gland is an exocrine gland in humans and other mammals that produces milk to feed young offspring.Mammals get their name from the Latin word mamma, "breast".The mammary glands are arranged in organs such as the breasts in primates (for example, humans and chimpanzees), the udder in ruminants (for example, cows, goats, sheep, and deer), and the dugs of other animals (for example, dogs ...
Genes expressed in the eutherian placenta that are important for the later stages of fetal development are in female marsupials expressed in their mammary glands during their lactation period instead. [46] After this period, the joey begins to spend increasing lengths of time out of the pouch, feeding and learning survival skills.
Theria (/ ˈ θ ɪər i ə / or / ˈ θ ɛr i ə /; from Ancient Greek θηρίον (thēríon) 'wild beast') is a subclass of mammals [2] amongst the Theriiformes.Theria includes the eutherians (including the placentals) and the metatherians (including the marsupials) but excludes the egg-laying monotremes and various extinct mammals evolving prior to the common ancestor of placentals and ...
A mammal (from Latin mamma 'breast') [1] is a vertebrate animal of the class Mammalia (/ m ə ˈ m eɪ l i. ə /).Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three middle ear bones.
The time when the monotreme line diverged from other mammalian lines is uncertain, but one survey of genetic studies gives an estimate of about 220 million years ago, [46] while others have posited younger estimates of 163 to 186 million years ago (though the already eutherian Juramaia is dated to 161–160 million years ago).
Boreoeutheria (/ b oʊ ˌ r iː oʊ j uː ˈ θ ɛr i ə /, "northern true beasts") is a magnorder of placental mammals that groups together superorders Euarchontoglires and Laurasiatheria.